100 pressure pads

Hi,

I have been asked to produce a matrix of 10 by 10 pressure pads linked to a PC and am wondering how feasible this is with arduino. Obviously none of the arduino boards have 100 analog inputs so does anyone know a way around that?

Thanks!

hi

i allways use the 4051 IC.
it scans 8 analog inputs and sends then to the arduino thru 1 analog pin.

so with 13x 4051 you can have 104 analog inputs. and it uses 13 analog pins on the arduino. so a MEGA would be nice to have.

its also possible with the uno but thats a little bit more tricky.

matrix of 10 by 10 pressure pads

Can you point to the supplier/info on the pads.. Various multiplex approaches might work.

Any idea on what "accuracy" is required (and how to even specify that)?

spirit:
i allways use the 4051 IC.
it scans 8 analog inputs and sends then to the arduino thru 1 analog pin.

Thanks will check that out.

13 analog inputs plus the 3 address select pins, so 16 total.
You might also consider DG406 for analog switch, 16 inputs, so only 7 chips needed. 4 address select lines.
http://www.digikey.com/product-search/en?vendor=0&keywords=dg406
Watch the series resistance of the switch, that may or may not have an impact on your sensor readings.

With 7 plus 4 select lines, you could use an SMD 328P design as well (Promini, Nano), no need to go to a Mega.

terryking228:
Can you point to the supplier/info on the pads.. Various multiplex approaches might work.

Any idea on what "accuracy" is required (and how to even specify that)?

No supplier at the moment, if you know of one (even one that provides an out-of-the-box solution) I'd be interested to know.

Accuracy is not super important. Most importantly I'd like to know whether someone has stood on a pad. If I can also record the pressure in some way that is a nice to have.

A 4067 multiplex chip is another option.

https://www.google.com/search?q=arduino+4067&num=100&lr=&as_qdr=all&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiD_vG7xKXKAhWGUBQKHZnZAOQQsAQIJQ&biw=1124&bih=615&dpr=0.95

If you can scan these pads sequentially, you could address all 100 of these pads and use a uniquely-wired 7 input AND gate to turn each one on when it is scanned. That sounds good in principle, but the amount of wiring would probably make it very difficult in practice, depending on the layout of this whole thing. If these pressure pads are to be spread out with enough space for various humans to be standing on them, the wiring might pose quite a few problems in terms of power needed and line lengths.